Organic Light Emitting Display Device

An organic light emitting display device including a substrate, a light emitting element on the substrate, and a driving thin film transistor supplying drive current to the light emitting element is disclosed. The driving thin film transistor includes a buffer layer on the substrate, a first polycrystalline silicon semiconductor layer on the buffer layer, a first oxide semiconductor layer contacting the first polycrystalline silicon semiconductor layer while being disposed thereon and including a first channel region, a first source region, and a first drain region, a gate insulating layer covering the first oxide semiconductor layer and the first polycrystalline silicon semiconductor layer, a first gate electrode disposed on the gate insulating layer, a first source electrode connected to the first source region, a first drain electrode connected to the first drain region, and a first light shielding layer disposed under the first oxide semiconductor layer while overlapping therewith.